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that the longest deck board would be just over 7 ft. long, so I could start with standard 8-ft. boards. This minimized expensive waste. Once I had the design squared away, it was easy to make up an accurate bill of materials. As a retail customer, I was able to negotiate only a relatively small discount on the initial bulk order. I knew I'd pay dearly for what I forgot-both in dollars and in lost time. On the other hand, liberal estimating could leave me with a lot of leftover materials that would be hard to store or to resell. In the end, my detailed material take-off was well worth the effort. On clean-up day, the only wood left over was a few treated 2x4s, which were quickly used in a landscaping project, and some 2x2s, which now serve as tomato stakes. Figuring a foundation-With the planning complete and the lumber stacked in the garage, safely out of the sunlight to keep it from warping, construction could begin. One side of the deck would be supported by three separate posts. Two of the posts were supported on a concrete-block retaining wall, which had been built two years earlier with the future deck in mind. The rebar-reinforced blocks had been filled solid with concrete, and the footing was oversized in order to support the deck weight. When it came time for the deck, all I had to do was install anchor bolts for the posts (photo at right). The third post had to be located in an exist- ing sidewalk. I used a hammer drill fitted with a masonry bit to "perforate" a 12-in. square area of pavement, and then chipped the rest away with a hammer and chisel. Then I was able to excavate a pyramid-shaped cavity 24 in. deep, so that the finished footing would spread the load on undisturbed soil below the frost line. The hole was filled with concrete around wire-mesh reinforcement, and a J-bolt was inserted to anchor the post. Sizing structural elements-A primary goal was to build a solid deck that would last at least 20 years and require an absolute minimum of maintenance. For this reason, I was conservative in sizing support members for strength and very careful at those points where wood rot could be expected. Although not required by our code, the galvanized steel bases I put under each post completely separate them from the concrete. A wood-to-concrete connection is one of the first places to rot, but the steel support provides a Y2-in. air gap, thus ensuring good ventilation at the end grain of the post. I decided that the posts would be 6x6s and the lengthwise support beam would be a pair of 2x12s. Local building code permitted 4x4 posts and a 2x8 beam, and upgrading these key components added only $55 to the cost of the project- a good long-term investment. Where the support beam meets a post, the post was double-notched at the top in order to support a 2x12 on either side of a 1 Y2-in. thick tongue. I sandwiched 2x12 scraps between the 2x12s of the support beam wherev- Photos by R. W. Missel The deck rests partially on a concrete-block wall that had been built some years before, but with the later construction of the deck in mind. The cores of the block had been reinforced and poured solid, so holes had to be hammer-drilled into the concrete for the anchor bolts (as shown in this photo), which were later grouted in place. er a splice was required, and also at the ends of the beam. All of these components were through-bolted with Y2-in. galvanized carriage bolts. The completed substructure formed a rigid, integral unit that helped to make the finished deck rock solid (photo adjacent page). Ledger details-The support beam, located just beyond the lengthwise centerline of the deck, carries about two-thirds of the deck's weight. The ledger, however, is equally important from a structural standpoint because it ties the whole deck structure to the house as well as supports the remainder of the deck. Attaching the ledger board was a simple matter. I just removed the siding and used lag screws to attach the ledger board to the rim joist of the house. The decking boards would have to be nailed to the ledger, and it was clear at the design stage that this wouldn't be easy. The 2x6 ledger provided only 1 Y2 in. of nailing surface, and even this was partially obstructed by the siding. As a result, the deck boards would have only an inch of bearing surface on the ledger. This connection would certainly be a weak link in the structure. And beside that, I didn't like the idea of driving all those nails so close to the aluminum siding, a material easily scarred by errant hammer blows. Instead, I nailed in a 2x4 flat to the top of the ledger (bottom photo, next page). The flat side of the 2x4 solidly supports the ends of the deck boards, and each of the 2x8 joists hanging from the ledger would have to be notched to clear the nailer. But the nailer was worth the trouble, because it reduced the likelihood of split end grain in the decking and also kept hammer dings in the siding to a minimum. Once the siding had been removed to in- stall the ledger, the house's main structural system was exposed to the elements. Rain and snow would reach into the voids and joints at the end of each deck board, and it April/May 1988 67